Templating briar

* 1st try to template briar
* Add home page
* Add README.md
* Fix markdown syntax
* Convert config.toml into config.yaml
* Add .gitignore
* Templating <head/> part
* Fix list and single page templating
* Convert pages directly with pandoc
* Configure link types: blogposts will have /post/ in front.
* Templating site menus
* Enable ATOM feed template
* Templating homepage with news